Engineering rockhead

Dando drilling rig.

Engineering rockhead is the rock surface at the base of an engineering soil (BS5930: 1999) and is of interest to the construction industry as it forms a solid platform on which foundations, piles and other infrastructure can be built. BGS is working on a proof of concept project that aims to develop a national model of depth to engineering rockhead.

The new model will be based on borehole records, site investigation reports, data in the National Geotechnical Properties Database and geological models and mapping. In areas where there is sufficient data, an engineering rockhead surface will be created that will indicate at what depth below ground surface it occurs. In other areas where quantification is more difficult, 'domains' will be created that describe the common typical engineering characteristics of the subsurface, so that engineers can more appropriately plan their foundation design.

This dataset should be useful to engineers, planners, developers and hydrogeologists who need to understand the properties of the ground. It might help, for example, with foundation design, the selection of suitable methods of drilling (rotary, percussion, etc.) or excavation tool requirements.